In this chapter, we demonstrated Istio's traffic management capabilities for traffic shifting, setting request timeouts, controlling Ingress and Egress traffic, circuit breaking to protect services from overload and attacks, and mirroring traffic from one route to another route.

These were the breakthroughs from the earlier concepts of achieving the same results either through coding in the application or by using libraries for every language. The capability to control traffic at the edge of the cluster gives operations staff ease-of-use to manage the application infrastructure dynamically and resiliently without needing intervention from developers. As an example, it is possible to completely block access to any external service from the distributed microservices application except whitelisted service entries.   

It is worth noting that all of the features we learned about in this chapter did not require making any changes in the application code, which makes service mesh very attractive. Similarly, security postures are implemented in application code traditionally. In the next chapter, we will look at Istio's security features so that we can implement security without making any changes to the application code. This is possible due to the Envoy sidecar implementation.